Democratic presidential candidate Hillary Rodham Clinton warned President George W Bush not to take any military action against Iran without getting congressional approval first.
"If the administration believes that any, any use of force against Iran is necessary, the president must come to Congress to seek that authority," Clinton said in a Senate speech yesterday.
Clinton, a member of the Armed Services Committee, voted in 2002 to give Bush the authority to use military force in Iraq - a vote that has prompted some Democrats to demand that she repudiate.
Since then, the New York senator has become an outspoken critic of Bush's handling of the war.
She said the new Democratic Congress must not let him make similar mistakes in the increasingly tense relationship with Iran.
"It would be a mistake of historical proportion if the administration thought that the 2002 resolution authorising force against Iraq was a blank check for the use of force against Iran without further congressional authorisation," Clinton said.
She also insisted the resolution authorising force against those responsible for the September 11, 2001 terrorist attacks did not allow for US action now against Iran.
Clinton, who has come under fire from anti-war Democrats, excoriated the previous Republican-controlled Congress for not questioning the administration over the past six years.